Mixtures of lines
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New Method needed?
Hi Graham, Ian,
We have come across a pedigree which has me scratching my head and I was hoping you could help me figure out how it should be entered into the GMS:
For example, Line name: 97B64-D5B1+ 98B69*X8
The way this was described to me was that we have a bag of seed that is 90% 97B64-D5B1 (a resistant line) and 10% 98B69*X8 (a susceptible line) or vice versa. Which proportion is which is unknown.
I see in the TDM, that there is a Management Method 322 (MULTI-LINE FORMATION SF). Would this be the correct method to use when entering it into the GMS?
Thank-you, Shawn
[edit]New method? Shawn
I think we should have a new method called ‘admixture’ rather than use the ‘multiline’ which is a specific purpose.
Could this be posted to the WICKI site.
Cheers
Ian
[edit]Mixture method Interesting to try using Wiki for discussion. Should answers go above or below questions?
Yes we need a new method for seed mixture. Not sure what admixture means but if that is the work OK. This should also have an attribute where you can give the proportions. We have one in IRIS methos 1120 I think. Graham
Brenda asks the following question:
We have a situtation that arises with some frequency that I'm wondering if you have a solution for. Within a plot of say 10 plants, seed from individuals might be harvested from each separately. In this case we use method 205 to create the new derivatives. Then in the following season, each of these lots would be grown out and in some cases the breeder decides that all (or some of ) the lots are similar enough to make bulking the individual lots logical and more practical.
Is there a method (I have looked, but I find the descriptions of the methods not quite clear enough for my piddly little brain) that allows the bulking of existing method 205 lots? It would be nice to be able to specify which of the method 205 lots ended up in the bulk lots, especially if it happened that there was clearly two different bulks that could be made (I'm thinking here of groups of monoecious versus gynoecious segregants).
What I do currently when the occasion arises, is go back to the sowing list and make a selected bulk (206), or random bulk (207) from the sowing list entry - and this works OK except for not tracking which individuals ended up in the bulk if in fact not all of them did.
I hope this makes some sense to you - if not, feel free to request clarification. Thanks for whatever insight you can offer.
Response from Graham: This is a common problem and apparently we discussed it before here. It is important to track the lines which went into the mixture. In IRRI we made a local method for this problem 1012 Mixture of hybrid seeds (I dont remember why we were so precise about hybrid seeds except that our situation involved mixtures of F1 seeds from different crosses (by accident)).
Ian is right it is a generative method. SetGen takes note of the limitation on number of possible progenitors recorded in the METHODS table. I propose to add the standard method 159 to the METHODS table as follows:
MID MTYPE MGRP MCODE MNAME MDESC MREF MPRGN MFPRG MATTR GENEQ MUID LMID MDATE 159 GEN S MIX MIXTURE SF ++ 0 0 0 212 0 1 0 20050521 ++ A mixture of lines in a self fertilizing crop
Notice MPRGN and MFPRG are zero which indicates a variable number of progenitors. SetGen will see this and allow any number. The ATTRIBUTE no 212 can be used to record the mixing proportions of the lines if wanted. (No application uses this at the moment). Hope this solves the problem definitively. Graham
